vendor/rails/railties/dispatches/gateway.cgi

   1 #!/usr/bin/env ruby
   2
   3 require 'drb'
   4
   5 # This file includes an experimental gateway CGI implementation. It will work
   6 # only on platforms which support both fork and sockets.
   7 #
   8 # To enable it edit public/.htaccess and replace dispatch.cgi with gateway.cgi.
   9 #
  10 # Next, create the directory log/drb_gateway and grant the apache user rw access
  11 # to said directory.
  12 #
  13 # On the next request to your server, the gateway tracker should start up, along
  14 # with a few listener processes. This setup should provide you with much better
  15 # speeds than dispatch.cgi.
  16 #
  17 # Keep in mind that the first request made to the server will be slow, as the
  18 # tracker and listeners will have to load. Also, the tracker and listeners will
  19 # shutdown after a period if inactivity. You can set this value below -- the
  20 # default is 90 seconds.
  21
  22 TrackerSocket = File.expand_path(File.join(File.dirname(__FILE__), '../log/drb_gateway/tracker.sock'))
  23 DieAfter = 90 # Seconds
  24 Listeners = 3
  25
  26 def message(s)
  27   $stderr.puts "gateway.cgi: #{s}" if ENV && ENV["DEBUG_GATEWAY"]
  28 end
  29
  30 def listener_socket(number)
  31   File.expand_path(File.join(File.dirname(__FILE__), "../log/drb_gateway/listener_#{number}.sock"))
  32 end
  33
  34 unless File.exist? TrackerSocket
  35   message "Starting tracker and #{Listeners} listeners"
  36   fork do
  37     Process.setsid
  38     STDIN.reopen "/dev/null"
  39     STDOUT.reopen "/dev/null", "a"
  40
  41     root = File.expand_path(File.dirname(__FILE__) + '/..')
  42
  43     message "starting tracker"
  44     fork do
  45       ARGV.clear
  46       ARGV << TrackerSocket << Listeners.to_s << DieAfter.to_s
  47       load File.join(root, 'script', 'tracker')
  48     end
  49
  50     message "starting listeners"
  51     require File.join(root, 'config/environment.rb')
  52     Listeners.times do |number|
  53       fork do
  54         ARGV.clear
  55         ARGV << listener_socket(number) << DieAfter.to_s
  56         load File.join(root, 'script', 'listener')
  57       end
  58     end
  59   end
  60
  61   message "waiting for tracker and listener to arise..."
  62   ready = false
  63   10.times do
  64     sleep 0.5
  65     break if (ready = File.exist?(TrackerSocket) && File.exist?(listener_socket(0)))
  66   end
  67
  68   if ready
  69     message "tracker and listener are ready"
  70   else
  71     message "Waited 5 seconds, listener and tracker not ready... dropping request"
  72     Kernel.exit 1
  73   end
  74 end
  75
  76 DRb.start_service
  77
  78 message "connecting to tracker"
  79 tracker = DRbObject.new_with_uri("drbunix:#{TrackerSocket}")
  80
  81 input = $stdin.read
  82 $stdin.close
  83
  84 env = ENV.inspect
  85
  86 output = nil
  87 tracker.with_listener do |number|
  88   message "connecting to listener #{number}"
  89   socket = listener_socket(number)
  90   listener = DRbObject.new_with_uri("drbunix:#{socket}")
  91   output = listener.process(env, input)
  92   message "listener #{number} has finished, writing output"
  93 end
  94
  95 $stdout.write output
  96 $stdout.flush
  97 $stdout.close